College of Science and Health Theses and Dissertations

Date of Award

Summer 7-13-2012

Degree Type


Degree Name

Master of Science (MS)



First Advisor

Anuj Sarma, Ph.D.

Second Advisor

Jesus Pando, Ph.D.

Third Advisor

Eric Landahl, Ph.D.


We present high resolution observations of 22 GHz H$_{2}$O masers toward the star forming region W3(OH), taken during two epochs using the Very Long Baseline Array telescope. We detected a total of 54 masers in observation BS198A, and 67 in BS198B, arranged in 3 groups. We determined that the observation BS198A took place during a period of quiescence, while BS198B was observed during a flaring period. We interpreted the maser morphology as lying on the eastern (Group 1) and western (Group 3) ends of an outflow, as well as near the outflow base (Group 2). We observed a velocity drift between the two epochs, which we interpreted as an acceleration of the outflow. We observed the Zeeman effect, and detected significant B$_{los}$ in 15 masers. Using accepted values for the density of the preshock region measured using OH thermal absorption lines, we calculated the density of the postshock region and found it to be in agreement with the theoretical values required for H$_{2}$O masing. We also observed the magnetic energy density to be on the order of or up to two orders of magnitude larger than the kinetic energy density, depending on the assumed velocity dispersion. This indicates that the magnetic field is dynamically significant in the W3(OH) region.

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